A useful collection of historical chance music, featuring Duchamp's Musical Erratum performed with electric motors and prepared piano – as well as a later instantiation for piano; two fascinating pieces by George Ribemont-Dessaignes, which are very convincing and have been too long forgotten; Francis Picabia’'s three-note proto-hyper-minimal La nourrice Americaine (another historically important work – even if unintentionally); and the four books of Cage's Music of Changes - an early recording of David Tudor'’s 1956 performance in Cologne. The accompanying book is informative and well illustrated with contemporary documents. L